The fresh perishables trade uses modified atmosphere technologies on bagged, or otherwise enclosed, and sealed, pallet unit quantities of perishables to preserve freshness and reduce market losses during distribution. Current systems require that a pallet bag be placed over a unitized pallet of perishables, which are placed in containers. The pallet bag is then sealed to a plastic sheet positioned on top of the pallet under the unitized containers of perishables. Once the pallet bag is sealed, desired quantities of one or more gasses are injected into the pallet bag, creating a modified atmosphere, which benefits the enclosed perishables. Bolejack, et al. U.S. Pat. Nos. 5,014,495; 5,046,302; 5,111,639; and 5,314,286; Forgnone, et al. U.S. Pat. No. 6,532,717; and MacLeod, et al. U.S. Pat. No. 4,821,489 describe such methods and apparatus.
There is a need to improve the automation and consistency of the current systems. Current systems require up to three persons to operate effectively. These systems produce completed pallets at a rate of up to about one per minute. The new methods and apparatus, with preferred embodiments, provide automated systems capable of reliably producing a finished pallet every 30 seconds, with fewer persons needed to operate the system.
Current systems require manual manipulation of the bags and the plastic sheets, and staples to hold plastic materials in place. The new systems eliminate the need for manual manipulation, and the need for staples.